my 16 year old daughter is a first time flyer and will be flying alone. She has social anxiety. will i be able to enter so i can help her find her gate etc/

With what you described, she shouldn't go alone, otherwise she may develope fear of flying maybe

Get a gate pass when you check in

@jonathan is wrong and reporting his answer to google as incorrect infornation. You can get gate only pass so you can see her all the way through security and to boarding area. Call the airline for assistance.

You can follow her to a point, but at the TSA checkpoint, you will have to part ways since you have no boarding pass.